I am trying to make the Back-To-School U-Neck Vest from Fitted Knits. I am at the point where I separated the front from the back; the pattern asked to bind off four stitches at the beginning of a couple rows. I did that and proceeded on, until I realized I had made a mistake. Now I want to go back to before I bound the first set of four stitches.

I am a relatively new knitter, so pics/diagrams/videos of how to do this would help me out a lot. Even a book source would be helpful.

I did the standard knit one, knit another, slip first knit stitch over the second bind-off method if is of assistance.